Combination hydraulic shearing and pressbrake machine

ABSTRACT

A combination hydraulic shearing and pressbrake machine is disclosed which includes auxiliary hydraulic cylinders in addition to main cylinders to actuate the ram. The auxiliary cylinders are held at rest during the shearing mode of operation but actuated together with the main cylinders during the pressbrake operation, in which the auxiliary cylinders serve particularly to support and maintain maximum parallelism of the ram. A control device is also disclosed which switches the operation of the auxiliary cylinders relative to the main cylinders and which further regulates the upper and lower limit positions of the reciprocating ram.

United States Patent Hongo 1 June 13, 1972 [54] COMBINATION HYDRAULIC1,333,201 3/1920 Beatty ..s3 s1s SHEARING AND PRESSBRAKE 3,550,425 12/1970v Cailloux ..72/386 MACHINE Primary ExaminerCharles W. Lanharn [72]Inventor: Toshio Hongo, 7-1 1, 5-chomc Konodai, Assistant Examine, Genep Crosby lchikawa- Japan Artorney-Linton & Linton [22] Flled. Sept. 11,1970 [57] ABSTRACT [21] Appl.-No.: 71,451

Y A combination hydraulic shearing and pressbrake machine is ['30]Foreign Application priority Data disclosed which includes auxiliaryhydraulic cylinders in addition to main cylinders to actuate the ram.The auxiliary cylin- Sept. 12, Japan ders are at rest i g the shearingmode ofoperation but [52] U.S.C| ..'..'....72/453, 72/324, 83/618, a u dog her wi h the main cylinders during the press- 83/639 brake operation,in which the auxiliary cylinders serve par- [51] Int. Cl. .Q ..B21j 9/02ticularly to support and maintain maximum parallelism of the [58] Fieldof Search ..72/453, 324, 326, 330, 332, ram. A control device is alsodisclosed which switches the 72/337, 338, 380, 385, 386, 389, 404, 325;83/639, operation of the auxiliary cylinders relative to the main cylin519 ders and which further regulates the upper and lower limit positionsof the reciprocating ram. [56] References Cited 5 Claims, 10 Drawingfigures UNITED STATES PATENTS Sevey ..83/618 PATENTEDJUM 13 I372 SHEET 1OF 6 INVENTOR. TOSH/O HO/VG 0 WM AT'T'QENELS PATENTEDJUNISIQYE 3,668,919

SHEET 20F s INVENTOR. TOSH/O HO/VGO ATTORNEYS PATENTEDJUH 13 1972 SHEET4 0F 6 FIGJ INVENTOR, TOSH/O HO/VGO ATTORNEYS PATENTEDJun 13 I972 SHEET5 0F 6 FIG.8

RTTORNEVJ PATENTEDJUN 1 3 I972 SHEET 6 [IF 6 PIC-3.10

27 H l'h. I

INVENTOR. TOSH/O HUNG 0 WM A TToR/VEYS COMBINATION HYDRAULIC SHEARINGAND PRESSBRAKE MACHINE This invention relates generally to machine toolsand particularly to a Working machine of the'type including incombination a hydraulic guillotine and a pressbrake for shearing andbending aworkpiece through the operation of a single ram.

The utility of machines of the class described is mainly in thespace-saving advantage. I However, many of these machines presentlyavailable have the drawback that the position of shearing is heldconsiderably apart from the position of bending owing to the increasedeffective height or cross-sectional coefficient of the ram which isrequired to withstand large bending stress applied during the pressbrakeoperation. Insufficient cross-sectional coefficient of the ram resultsin deflected working plane of the ram and hence in inaccurate workfinish. The distance between the shearing and the pressbrake positionwill be necessarily greater the greater the bending strength of the ram,which would lead to difiicult maneuvering of the machine and hence toretarded working speed. Means have been proposed to eliminate thisdifficulty, and such means for example include a removable plateform ofsufficient height to permit the operator to work at a level adjusted toincreased height of the ram. The provision of such plateform has requirdadditional floor space, or in some cases an underfloor pitto enable theplateform to retract therein.

Whereas, it is the primary object of the present invention to eliminatethe above-noted difficulties of existing machines.

It is a specific object of the invention to provide an improvedcombination shear and press machine including a single reciprocating ramof relatively low profile.

It is another object to provide an improved machine including mainhydraulic cylinder to actuate the ram and auxiliary hydraulic cylindersto support and maintain maximum parallelism of the ram during bendingoperations.

It is a further object to provide means for controlling and switchingthe operation between the main and the auxiliary set of cylinders. Theseand other objects and features of the invention will be betterunderstood from the following detail description taken in connectionvwith the accompanying drawings illustrating a preferred embodiment, andin the drawings:

FIG. I isa front elevation of a combination shear and press machineembodying the invention;

FIG. 2 is a cross-sectional view .of thesame taken on the line Il-ll ofFIG. 1;

FIG. 3 is a cross-sectional view on enlarged scale taken along the lineIll-Ill of FIG. 1; FIG. .4. is a cross-sectional view taken on the linelVlV of FIG. 3, showingthis section (left-hand side) as connected to thechange-over valves righvhand side) which are employed to change thedirection of flow of oil in the hydraulic system according to theinvention;

FIG. 5 is a cross-sectional view taken on the line V-V line of FIG. 3;

FIG. 6 is a perspective view of a part of the machine showing a rotarylever and its associated cam member;

FIG. 7 is a cross-sectional view showing a cam in pressbrake positiontaken on the line VII-VII of FIG. 3;

FIG. 8 is a cross-sectional view taken on the line VIII-VIII of FIG. 3;

FIG. 9 is a view similarto FIG. 7 but showing the-cam as in shearingposition;

FIG. 10 is an oil path circuit utilizedto schematically illustrate theswitching between the pressbrake mode of operation and the shearing modeof operation.

' The machine 10 according to the invention generally comprises a framestructure 1 1 including a pair of laterally spaced side plates 12, upperfront plate 13 and lower front plate 14. A ledge 15 extends rearwardlyof the machine from the upper front plate 13 and has mounted thereon anoil pressure generator 16 and a drive motor 17. The generator 16compactly accommodates therein a pump, tank, control valves,

pilot valves, conduits and so on all in a manner well known in the art.A rod 18 extends between and is connected to the opposed side plates l2adjacent to the lower front plate 14. A ram actuating pedal 19 isattached to the rod 18. The frame structure 11 further includes atransverse beam member 20 extending between the side plates 12, to whichbeam is secured a work bed 21 extending forwardly of the machine forsupporting-thereon a workpiece during the shearing mode of operation. Astationary cutter 22 is secured to the inner end of the beam 20.

The upper front plate l3'has its lower end portion recessed as at 23 forinserting one end'of a tool bracket 25 which is secured in place bymeans of bolts 26. Subjacent to and in vertical alignment with the toolbracket 25 is provided a ram 27 which has secured to its lower portion amoving cutter 28 coacting with the stationary cutter 22. The bracket 25has a tapered edge or male die 29 for engagement with a correspondinglychamfered female die 30 secured by clamping bolts 31 to the upper end ofthe ram.

In front of the ram 27, there is provided a retaining plate 32 which issecured at two extreme ends to the side plates 12 by means of bolts 33and across compression springs 34. This retaining plate is forceddownwards against tension in the springs 34 by descending ram 27 andwill retain a workpiece in position. The retainer 32 returns to normalposition by the action of the springs 34 as the ram 27 ascends back toits rest position. The function of the springs 34 may be of coursereplaced by a hydraulic cylinder where heavy duty operations arerequired. I

The height of the bed 21 above the floor is normally about 60 to 70cm,while the distance between the floor and the upper end of the ram 27 isabout to cm, so that the difference of the operational level betweenshearing on the bed 21 and bending on the. die 30 of the ram is about 15to 30cm, preferably about 25cm for maximum operators comfort.

Projecting rearwardly from the ram 27 is a support member 35 adapted tosecure thereto a back gage 36 comprising a screw shaft 37 joumalled inan elongated open-bottom box 38 and a slider 39 having a threaded member40 for threaded engagement with the screw shaft 37. Manual or poweredrota tion of the screw shaft 37 moves the slider 39 longitudinally ofthe shaft 37. The slider'39 has an end stop 41 disposed in abuttingrelation to a workpiece for determining the length of the latter to becut corresponding to the distance between the stop 41 and the cuttingposition of the ram 27.

There are provided main hydraulic cylinders 42 having their respectivepiston rods 43 connected to the opposite ends of the ram 27 foractuating the same in the shearing and bending cycles of operation.There are further provided according to the invention auxiliaryhydraulic cylinders 44 at symmetric positions inwardly of the maincylinders 42 as shown in chain line in FIG. 1. These auxiliary cylinders44 have their respective piston rods 45 disposed in abutting relation tobut normally apart from the ram 27. The piston rods 45 of the auxiliarycylinders 44 are arranged to move upwardly into contact with a medialportion of the ram 27 together with the upward stroke of the maincylinders 42 during the bending cycle of operation in which a workpieceis pressed and bent on the die members 20 and 30. During the shearingcycle of operation, the auxiliary cylinders 44 are held at rest and neednot operate to support and protect the ram 27 against the load ofshearing which is usually relatively small. However, the stress ofbending which occurs during the pressbrake operation of the machine isconsiderably large and pronounced at the medial area of the ram, whichwould often produce physical deflection in the ram and adversely affectthe accuracy to which a workpiece is pressed and bent, unless properremedy is provided. This problem has been solved by the arrangementaccording to the invention in which the piston rods 45 of the auxiliarycylinders 44 approach at the time of pressbrake and engage in abuttingrelation with the lower end face of the ram 27, thereby supporting thesame against the influence of bending load applied during the pressbrakemode of operation. The

operation of the auxiliary cylinders 44 relative to the main cylinders42 will be described more fully hereinafter.

Designated at 46 is a plate chute extending from behind the stationarycutter 22 and having a downwardly inclined slide surface fortransferring therealong and removing the machined workpiece out of themachine. The chute 46 has an opening 47 through which the piston rod 45of the auxiliary cylinder 44 moves into and out of abutting engagementwith the ram 27.

Now, referring to FIG. 10, there is schematically shown an oil pathswitching circuit 50 for controlling the supply of oil pressure to themain and auxiliary cylinders. The circuit 50 includes a main valve 51, achange-over valve 52, a pump P, an oil reservoir RV and various oilpassage lines connecting between the valves and the hydraulic cylinders.More specifically, the main valve 51 has an outlet A connected via line53 to the approach side of the main cylinder 42 in pressbrake positionand another outlet B connected via line 54 to the return side of themain cylinder 42. The change-over valve 52 associated with the auxiliarycylinder 44 is connected via branch line 55 to line 53 on the approachside of the main cylinder 42. The change-over valve 52 has an outlet Cconnected via line 56 to the approach side of the auxiliary cylinder 44and another outlet D via line 57 to the return side of the auxiliarycylinder 44. A plunger 51a of the main valve 51 is connected byconnecting rod 51b to an oil path switching device later described. Aplunger 52a of the change-over valve 52 is connected by connecting rod52b through a link 520 to the switching device.

While the left-hand side half of the circuit 50 just described isomitted in FIG. 10, it is obvious that a similar circuit may beconnected there in parallel for the same purpose.

An oil path switching device 60 according to the invention essentiallycomprises a main valve and change-over valve control unit and a ramstroke regulating unit. The device 60 is shown in FIG. 3 through FIG. 8as set in the pressbrake position of the tool machine 10.

The valve control unit includes a frame member 61 provided at its upperend portion with a yoke 62 for supporting a bell crank 63, at itsintermediate portion with a bearing 64 and at its lower end portion witha bearing 65, both bearings being adapted to journal therein a cam shaft66. The frame 61 is further provided with a bearing 67 intermediatebetween the upper and lower bearings 64 and 65 for supporting a rotarylever 68. The cam shaft 66 has at its upper portion a reduced neck 69 atwhich one end of the bell crank 63 is attached. The cam shaft 66 isrecessed as at 80 adjacent to the upper end face of the bearing 64 forengagement with a shifting lever 81. The shaft 66 has a cam 83 attachedthereto intermediate between the upper and lower bearings 64 and 65, andfurther has a recess 83 adjacent to the upper end face of the lowerbearing 65 for receiving a lever member 84.

Designated at 85 is a pin connecting the bell crank 63 pivotally to theyoke 62. One end of the bell crank 63 is secured, as already stated, tothe reduced neck 69 of the cam shaft 66, and the other end of the crank63 is connected to the connecting rod 51b of the main valve 51. Withthis arrangement, vertical movement of the cam shaft 66 rotates the bellcrank 63 which in turn actuates the plunger 510 so as to open and closethe main valve 51.

The shifting lever 81 is partly fitted within the recess 80 in the camshaft 66 and secured to a supporting member 86 mounted on the cam shaft66. The lever support 86 has one end connected to the connecting rod52b, as seen in FIG. 4, which rod is further connected via suitable link520 to the plunger 52a of the changeover valve 52. With thisarrangement, rotation of the shifting lever 81 changes the operatingposition of the change-over valve 52.

The rotary lever 68 is rotatably mounted on a shaft 87 journalled in thebearing 67 and has its front end connected to one end of a pull bar 88(FIGS. 6 and 7). The other end of the bar 88 is connected to a pedal 89resiliently supported on a spring 90 as seen in FIG. 3. The rotary lever68 is provided at its side facing the cam shaft 66 and at symmetricalpositions with cam followers 91a and 91b as shown in FIGS. 6 and 7. Thecam shaft 66 is provided centrally with the cam 82 which issubstantially triangular in plane and which has integral therewith camdogs 92a and 92b on the side of a ram stroke regulating unit laterdescribed. The cam dogs 92a and 92b are disposed for engagementrespectively with a lower limit dog 109 and a shearing upper limit dog114, in the ram stroke control. The cam 82 is provided with grooves 95aand 95b at positions engageable with the cam followers 91a and 91b,respectively, when the shifting lever 81 is rotated.

It will be appreciated that the rotary lever 68 may be alternativelyprovided with a groove for receiving a pin or roller attached to the cam82 instead of the foregoing arrangement. It will be also understood thatthe shifting lever 81 need not necessarily be separately installed, orany other suitable means may be employed for rotating the cam 82. Theshifting lever may be for example attached to the cam, in which case theconnecting rod 52b may be connected directly to the cam.

The ram stroke regulating unit according to the invention comprises avertical base secured to the ram 27 and provided at its upper part witha bearing 101 for rotatably supporting a screw rod 102. The screw rod102 is threaded throughout its lower half portion and has a bevel gear103 fixedly mounted at its top, which gear 103 is driven by a matingbevel gear 103'. The drive bevel gear 103 is secured to one end of ashaft 104 joumalled in bearing 105 and extending horizontally across theram 27. The other end of the shaft 104 has a handle 106 secured in placeby means of a nut 107. The screw rod 102 has mounted thereon an upperlimit dog 108 and a lower limit dog 109 for limiting the stroke of theram 27 during the pressbrake mode of operation. The lower limit dog 109is loosely mounted on the non-threaded portion of the screw rod 102 andhas one side slidably inserted in a guide groove 110 in the base 100 andnormally urged against the wall of the groove 110 by a push screw 111having a handle 112 as shown in FIG. 8. Releasing the push screw 111from the lower limit dog 109 permits this dog to move in the guidegroove 110 and along the screw rod 102, so as to set the lower limitposition of the ram 27 during the pressbrake operation. In thisposition, the lower limit dog 109 is held in abutment against the upperface of the cam dog 92b as seen in FIG. 3. The upper limit dog 108 isheld in threaded engagement with the threaded part of the screw rod 102and has one side slidably inserted in a guide groove 113 formed in thebase 100, so that the dog 108 may move up and down with rotation of thescrew rod 102 so as to set the upper limit position of the ram 27 duringthe pressbrake position. In the pressbrake mode of operation, the upperlimit dog 108 moves upward with the ram 27 and comes in abutment withthe lower face of the cam dog 92a.

There is provided another limit dog 114 for limiting the upward strokeof the ram 27 during the shearing operation. This dog 114, hereinafterreferred to as shear limit dog, is disposed side by side with the lowerlimit dog 102 and attached to the side of the base 100. When the machineis switched into a shearing mode of operation, the shear limit dog 1 14is brought into contact with the lower face of the cam dog 92a as shownin FIG. 9. It is to be noted here that it is not necessary to provide alimit dog for limiting the downward stroke of the ram 27 during theshearing operation.

In the embodiment above described, there is further provided means forimparting a positive motion to the ram 27 during the shearing operation.This means comprises a cam 115 and a lever member 84 as specificallyshown in FIG. 8. The cam 1 15 is secured to the lower end face of theshear limit dog 114 and has an inclined face disposed on the side of thecam shaft 66. The lever 84 is pivotally connected by pin 116 to thebearing 65 of the cam shaft 66 and has one end in threaded engagementwith a screw 117. The screw 117 has its forward end disposed in abuttingrelation to the inclined face of the cam 115. A spring 118 has one endsecured to the frame member 61 and the other end to the tip end of thelever 84 so as to retain the lever 84 resiliently in position. As thecam shaft 66 ascends until the recess 83 reaches the lever 84, the lever84 fits into this recess, with the result that the ram 27 can move evenwith the pedal 89 released during the shearing operation.

Having thus described the construction of the machine embodying thepresent invention, the following description will now deal with itsoperation. i In the pressbrake mode of operation, the cam follower 91ais engaged in the cam groove 95a. Now, depressing the pedal 89 to pullthe rod 88 causes the rotary lever 68 to rotate clockwise, which in turnlowers the cam shaft 66 to move the bell crank 63 counter-clockwise.This actuates the plunger 51 to open the outlet A of the main valve 51,thereby effecting the approach operation of the main cylinder 42.Simultaneously as this occurs, the oil pressure flows through the branchline .55, change-over valve 52, line 56 into the auxiliary cylinder 44to actuate this cylinder to make an upward stroke. Operation of bothmain and auxiliary cylinders moves the ram 27 upwards until the upperlimit dog 108 abuts against the lower end face of the cam dog 95b, andthe cam 82 is lifted, whereupon the cam shaft 66 begins to ascent tocause the bell crank 63 to move clockwise. This movement of the bellcrank 63 causes the plunger 51:: to move back to close the main valve 51and stop the ram 27.

Releasing the pedal 89 lifts the cam shaft 66 to its upper limitposition, in which the main valve plunger 51a is withdrawn so as to openthe outlet B of the main valve 51. This causes the ram 27 to descenduntil the lower limit dog 109 abuts against the upper end face of thecam dog 95b, when the cam 82 and the cam shaft 66 begin to descend andreturn to the position shown in FIG. 3.

A desired lower limit position of the ram 27 in the pressbrake mode ofoperation may be easily selected and set by slackening the screw 111 andchanging the position of the lower limit dog 109. The upper limitposition of the ram 27 may be determined by the position of the upperlimit dog 108 which is variable by manipulating the screw rod 102.

Rotating the shifting lever 81 clockwise moves the ram 27 upwards untilthe shear limit dog 114 abuts against the lower end face of the cam dog95a and stops the ram 27 in the upper limit position in the shearingmode of operation. This rotation of the lever 81 setsthe change-overvalve 52 in closed position, so that the auxiliary cylinder 44 is heldat rest during the shearing operation.

With the machine set in the shearing mode of operation, the cam follower91b is engaged in the groove 95b of the cam 82. In this position,depressing the pedal 89 causes the cam shaft 66 to move upwards and thebell crank 63 to move clockwise to pull the plunger 51a, which in turnopens the outlet B of the main valve 51 to impart a downward movement tothe ram 27. In this instance, with ascending cam shaft 66, the lever 84fits into the recess 83 to lock the shaft 66 in position. Therefore, thepedal 89 may be readily released.

According as the ram 27 moves downwards, the screw 117 of the lever 84is pushed by the cam 115 so that the lever 84 disengages from the recess83, whereupon the pedal 89 is lifted under the influence of the spring90. This causes the cam shaft 66 to descend and the ram 27 to ascenduntil the shear limit dog 1 14 contacts the lower end face of the camdog a, lifting the cam 82 and hence the cam shaft 66. The bell crank 63begins to rotate and the main valve 51 closes to stop the ram in theupper limit position in the manner already described.

Where the machine is not equipped with the cam and lever 84, the pedal89 may be kept depressed until a shearing cycle is completed and may bereleased upon completion of the shearing operation, whereupon the pedalis urged upwards by the spring 90 to repeat the foregoing procedure tobring the ram back into its upper limit position.

While the invention has been described with a specific embodimentrelative to a shearing and bending machine, it will be appreciated thatthe principles of this invention may be equ ly applied to an apparatusfor testing the tension and compression of materials. It will be alsounderstood that the invention is not to be limited to the specific formand construction of the machine herein advanced, but many modificationsand changes may be made therein without departing from the scope of theappended claims.

What is claimed is:

l. A combination hydraulic shearing and pressbrake machine whichcomprises a reciprocating ram, a set of main hydraulic cylindersactuating said ram and a plurality of auxiliary hydraulic cylinders eachhaving a piston rod disposed normally in spaced apart relation to saidrarn during the shearing mode of operation, said auxiliary hydrauliccylinders being arranged to operate in the pressbrake mode of operationtogether with said main cylinders to actuate the ram.

2. In a combination hydraulic shearing and pressbrake machine of theclass described including main cylinders and auxiliary cylinders, an oilpath switching device which comprises a main and change-over valvecontrol unit and a ram stroke regulating unit, said valve control unitincluding a frame, a cam shaft slidably journalled in bearings securedto said frame, a bell crank having one end secured to said cam shaft, amain valve supplying an oil pressure to the main cylinders, a plungerconnecting between the other end of said bell crank and said main valve,cam means mounted on said cam shaft, a rotary lever pivotted on saidframe and disposed to engage said cam means, a pedal resiliently held inposition and connected to said rotary lever, a shifting lever connectedto said cam shaft, a change-over valve supplying an oil pressure to theauxiliary cylinders, and a plunger connecting between said shiftinglever and said change-over valve, and said ram stroke regulating unitincluding a screw rod parallel with said cam shaft and rotatably mountedin said frame and means operatively associated with said screw rod forsetting the upper and lower limit positions of the ram.

3. The machine as defined in claim 2 wherein said cam means is providedwith grooves for receiving said rotary lever.

4. The machine as defined in claim 2 wherein said cam means is contactedby cam follower means.

5. The machine as defined in claim 2 wherein said ram stroke regulatingunit further includes dog members movable along said screw rod to selectthe upper and lower limit positions of the ram.

1. A combination hydraulic shearing and pressbrake machine whichcomprises a reciprocating ram, a set of main hydraulic cylindersactuating said ram and a plurality of auxiliary hydraulic cylinders eachhaving a piston rod disposed normally in spaced apart relation to saidram during the shearing mode of operation, said auxiliary hydrauliccylinders being arranged to operate in the pressbrake mode of operationtogether with said main cylinders to actuate the ram.
 2. In acombination hydraulic shearing and pressbrake machine of the classdescribed including main cylinders and auxiliary cylinders, an oil pathswitching device which comprises a main and change-over valve controlunit and a ram stroke regulating unit, said valve control unit includinga frame, a cam shaft slidably journalled in bearings secured to saidframe, a bell crank having one end secured to said cam shaft, a mainvalve supplying an oil pressure to the main cylinders, a plungerconnecting between the other end of said bell crank and said main valve,cam means mounted on said cam shaft, a rotary lever pivotted on saidframe and disposed to engage said cam means, a pedal resiliently held inposition and connected to said rotary lever, a shifting leVer connectedto said cam shaft, a change-over valve supplying an oil pressure to theauxiliary cylinders, and a plunger connecting between said shiftinglever and said change-over valve, and said ram stroke regulating unitincluding a screw rod parallel with said cam shaft and rotatably mountedin said frame and means operatively associated with said screw rod forsetting the upper and lower limit positions of the ram.
 3. The machineas defined in claim 2 wherein said cam means is provided with groovesfor receiving said rotary lever.
 4. The machine as defined in claim 2wherein said cam means is contacted by cam follower means.
 5. Themachine as defined in claim 2 wherein said ram stroke regulating unitfurther includes dog members movable along said screw rod to select theupper and lower limit positions of the ram.